The other part comes from all the external and internal exposures a person experiences during their lifetime, which can range from pollution to infections to diet and lifestyle. Cumulatively, these exposures—and the body’s biological response to them—make up what scientists have termed the exposome.
A team led by scientists at Harvard Medical School has now conducted what may be the largest-scale study to date to quantify the relationships between exposures and health outcomes, testing more than 100,000 associations. The work demonstrates the importance of studying potential environmental disease risks in aggregate rather than one at a time.
Analyzing preexisting survey data from U.S. populations, the researchers found that individual exposures had only a moderate impact on health outcomes—but that this impact increased when considering multiple exposures at the same time.
